The present invention relates to slurry compositions. The slurry compositions are useful for polishing and especially for planarizing surfaces in the microelectronics industry. More particularly the present invention relates to increasing the topological selectivity of planarizing compositions by employing slurry compositions containing solid lubricant particles. An added advantage of such slurry compositions is that the reduced friction reduces delamination (peeling) due to polishing, which is particularly important in polishing low k and porous low k dielectrics, and reduces defects such as scratches.
In the fabrication of microelectronics components, a number of steps involved are polishing, especially surfaces for chemical-mechanical polishing for the purpose of recovering a selected material and/or planarizing the structure. Accordingly, over the years, a number of vastly different types of polishing processes to remove material, sometimes in selective areas, have been developed and are utilized to varying degrees.
For instance, in microelectronics planarization metal or insulator layers are deposited conformably into etched trenches of a substrate after which a need exists to planarize the surface with chemical mechanical planarization (CMP). With device dimensions becoming smaller and smaller involving not only narrower lines but also thinner layers both in front-end, and back-end of the line applications, post CMP specifications for permissible deviation from perfect planarity are becoming tighter. The deviation from perfect planarity, referred to as a step, is detrimental due to depth-of-focus issues in subsequent lithography steps. Also, this deviation in the case of oxide polish can lead to field threshold problems in isolation regions, while in the case of metal polish can cause shorts in the next metal level. For devices manufactured in the near future it is important to achieve a post-planarization step-height of less than 100 Angstroms on a 100 micronsxc3x97100 microns test site. Another important issue is surface damage, such as, peeling and scratches, particularly in polishing low k and porous low k dielectrics.
The present invention provides for improving the topological selectivity of the polishing by including solid lubricant particles in the polishing composition. This is achievable by the present invention in a single step CMP process without the need for any auxiliary process steps or auxiliary filling structures.
More particularly, an aspect of the present invention relates to a polish composition comprising abrasive particles and about 0.03% to about 10% by weight of solid lubricant particles.
Another aspect of the present invention relates to a method for polishing a surface by providing on the surface a liquid slurry composition comprising abrasive particles and solid lubricant particles in an amount sufficient to increase the topological selectivity of the composition when contacting the surface with a polishing pad; and contacting the surface with a polishing pad.
A still further aspect of the present invention relates to a method for polishing a surface by providing on the surface a liquid slurry composition comprising solid lubricant particles in an amount sufficient to reduce scratching and/or delamination when polishing thin films; and polishing said surface. The thin films are typically 2 xcexcm or less.
Other objects and advantages of the present invention will become readily apparent by those skilled in the art from the following detailed description, wherein it is shown and described preferred embodiments of the invention, simply by way of illustration of the best mode contemplated of carrying out the invention. As will be realized the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, without departing from the invention. Accordingly, the description is to be regarded as illustrative in nature and not as restrictive.